Infinite Tunnel Droste effect
here is a messy node setup that  could be turned into one  python node "I'll try to do that " :
this is the node setup

this is the node-group 

the object index in the node-group should be that of the "object of interest", also the is object is unwrapped before. 


finally here is a quick simple render :


*the UV and ID outputs of the node group are only added to ease hooking up more nodes sequentially